In further on Monday 14 January, QF405, the 0630 hours from SYD down to MEL did not take off until 0808.  As at 0931, A332 VH-EBD was holding in an unusual location above Humevale (east of Whittlesea) so its 0805 hours scheduled arrival will become 0945 or later.
Similarly, QF605 from BNE to MEL has been holding for quite some time a little to Kinglake's west, again not a usual location for this to occur.  This 0610 hours BNE - MEL took off if anything a few minutes early at 0619 hours so B738 VH-VXS will be at least 15 minutes later than its 0930 hours timetabled arrival.
A388 VH-OQB on QF94 from LAX to MEL, due in at 0950 hours, was running early but won't be now as it is holding above Mt Baw Baw in west Gippsland.
Departures have been occurring at MEL (such as QF418 taking off at 0935 for SYD) so not sure why the inbound delays.  ATC has said the airport is 'closed' (to inbounds) so it may be a problem with debris on a runway, or low visibility on approach?
UPDATE: QF415, the 0800 hours SYD - MEL that took off at 0830 hours (B738 VH-VYB) is diverting to CBR having got as far south as Mt Buller (Vic).
The airport reopened at about 1000 so QF405 from SYD landed at 1001 hours, so at its gate it will be 121 minutes late.
QF605 from BNE landed at 1003, so its at gate time will mean its arrival is 38 late.
QF94 was looking as if it may have to divert to AVV but is about to land on runway 34 at about 1010, so it will be about 25 minutes late at gate.
QF477 from SYD to MEL, the 0750 hours, took off at 0827 with VH-VZQ, proceeded as far south as Mt Buller but then diverted to CBR, arriving at 1013 when it should be in MEL at 0925.
The 0910 hours MEL up to BNE, QF610 (B738 VH-VXG) was in the sky at 1002 so should arrive at 1100 hours, 40 minutes late.